haberlandt2008

In this case we are using the lens of a digital compact camera, Pentax Optio s60, to get a higher magnification (=higher instability).

Not enough yet.

a “12vdc massive motor from a savaged printer” costs at ona radio (barcelona) about 10 euros… brand new

i just purchased a water pump (350 l/h at 9vdc), 7,68 ex vat, and two sets of gears by cebek

fun guaranteed

DIY Spectophotometer

Measurement of light absorption by a spectrophotometer is used to detect and identify molecules and to measure their concentration in solution. The fraction of the incident light absorbed by a solution at a given wavelenght is related to the thickness of the absorbing species.

Instructions at:

RSC

Parts list

·Photometer

Printed circuit board, plug-board, or photoresist board
Voltmeter or digital multimeter
Plastic or glass cuvettes
Total cost for photometer consumables is under £4.00

·Spectrophotometer

White light source
Diffraction grating, prisms or coloured filters. (Note: gratings are available at modest cost and work better than prisms.)
Lenses
Optical bench or stands and clamps; black cloth
Resistors: 4.7 k; 2.2 k; 1.0 k
LED: orange, 5 mm
LDR
Op amp: 3140
Socket: eight-pin
Battery clips
Soldering iron, solder,
Blu-Tack, tape and card

Pros
Way to go. Did arduino 101. Quantitatively precise. Totally DIYBio. The rest of the blablabLAB members are doing electronics. Fun. Must definitely Do.

Cons
Electronics are hard

pHmeter

When cultivated in aqueous culture the cell growth can be determined by following the optical density.
On the other hand, when produced by solid cultivation the growth can be determined only indirectly, such as, through determination of the protein content of the fermenting solids. In this work the possibility of estimating cell growth by pH determination was verified. From the results it was concluded that pH and protein production (solid or surface culture) or cell content (liquid culture) correlate well, therefore pH determination seems to be a good method to determine cell growth.

Pros
Cheap, easy, fast. Useful as a state of the batch measure.

Cons
We are not able to adjust pH continuously for optimum spirulina performance.

Pressure measurement, or how to use balloons in science
Estimate growth of A. platensis by measuring the oxygen produced by connecting the bioreactor to a balloon.

Pros
Very easy, very cheap, qualitatively accurate. Must Do

Cons
Quantitatively innacurate.

T.S.

References

Cogne G et al. (2001). Growth monitoring of a photosynthetic micro-organism (Spirulina platensis) by pressure measurement. Biotechnology Letters 23(16):1309-1314

Helena L et al. (2002). Spirulina platensis growth estimation by pH determination at different cultivations conditions. Journal of Biotechnology 5(3):251-257

Tavener SJ, Thomas-Oates JE (2007). Build Your Own Spectrophotometer. Education In Chemistry 44(5)

Nelson DL, Cox MM. (2000). Lehninger Principles of Biochemistry. 3^rded. Worth Publishers, New York.

In order to have a microscope to check the cultivated cells we’ve been experimenting inverting camera lenses to get some magnifications, here are the first results.

In this case we are using a Minolta reflex zoom lens at 28mm and infinite focus placed upside down in front of a Sony H20 compact camera with the optical zoom at x10. A support is essential to have a stable image.

A higher magnification and a built-in microscope is required though.

Seeing the results from the guys of Hackteria we got motivated to build something really similar. So once we get our webcam we’ll try out.

Coming soon new images!